After graduating from high school in St. Louis, Missouri, Miller attended that city's Washington University, where he was a member of the dramatic and musical comedy groups. He played in the band, edited the school newspaper, and started his professional career in radio, making his debut in his freshman year. Without previous training, he applied for a job at a local radio station but was turned down. Undeterred, he returned a few days later to audition as a character actor. He played all the roles in a sketch he had written himself, including an Englishman, a Frenchman, an Italian, an American gangster, and a straight man. This time he was hired as a summer replacement. After graduation, he moved to Chicago where he soon became a leading announcer and actor. Before leaving for Hollywood in 1944 he was appearing on an average of 45 broadcasts a week. Variety dubbed him "Chicago's one-man radio industry". His second day in town he began landing parts in two major programs and a number of shows. He either narrated or appeared in, among others, The Millionaire (1955) (as narrator "Michael Anthony"), Insight (1960), The Famous Adventures of Mr. Magoo (1964), The Adventures of Ozzie and Harriet (1952), Space Patrol (1950), The George Burns and Gracie Allen Show (1950), The F.B.I. (1965), and Love, American Style (1969), among many others. Miller also narrated films including My Country 'Tis of Thee (1950), which was nominated for an Academy Award, and the pseudo-documentary Unidentified Flying Objects: The True Story of Flying Saucers (1956). He won Grammy Awards in 1965 and 1966 for his recordings of stories by Dr. Seuss. His hobbies including woodworking, collecting menus, bookbinding, painting, photography, and collecting rare phonograph recordings. He also recorded the entire Holy Bible on record, the first time that had ever been done. It contained more than a million words, and took a week and a half to play.